Wedding and Engagement Rings
Choosing the Perfect Engagement Ring or Wedding Band for Your Spouse
By Nina Callaway, About.com Guide

The wedding bands and engagement rings you choose will be one of the most enduring pieces of your wedding day. Not only are they an important element of becoming married, but they are also a longlasting symbol of your love and commitment. Therefore, you'll want to choose jewelry that is timeless and high quality. Ultimately, you'll also want to be an educated consumer who knows what you're getting for your dollar. 


Style of Engagement Rings: There are several ways to pick an engagement ring. Since she'll be wearing for the rest of her life, you'll want to make sure you get it right. One option is to propose without an engagement ring, and then go to pick it out together. While this is a sure way to know that she'll like the ring, some people feels this robs the engagement ring of some of its romance. They may prefer to bring her best friend or mother shopping with them, or have a romantic date of preview shopping for the ring. Another option is to study what kind of jewelry she wears - from what kind of metal, to whether it's contemporary or classic, even perhaps "borrowing" a ring to take with you to the jewelry store, which will also help you know her ring size.

Style of Wedding Bands: 
Follow your instincts with the look and design of your ring, while asking yourself if it will be a design you'll be comfortable wearing every day for the rest of your life. The traditional plain gold wedding band will be in style for years to come. If that's too plain for you, consider a beaded edge or an engraved style. For a slightly flashier look, what about channel-set diamonds? You should also think about whether to engrave your wedding rings, and what they will say. 

Ultimately, choose a wedding band that you feel is expressive of your style and personality. I've heard of a couple that chose to have wedding bands custom-made that resembled bicycle gears, reflecting their mutual love of bike-riding. There's really no wrong answer as to what style you should choose. 

Gold, Silver or Platinum?
Many couples choose the metal for their bands by matching it to their engagement ring. However, don't feel bound to this. A bride can choose to wear her engagement ring on her right hand, and wedding ring on the left. Also, each of you can wear a similar style in different metals. Consider which metals each of you wear regularly - is most of her jewelry silver? Is his watch gold? 

Primary engagement ring and wedding band metal choices include: 

• Yellow gold: 
  the most traditional of metals; for many gold is a symbol of the warmth and love of a marriage. Look at the mark inside the band to see what quality the gold is - usually 14k, 18k, or 24k. While 24k is the most pure, it is also the softest. If you work with your hands, you may want to choose 14k or 18k to prevent scratches.
• White Gold:
  A hot trend because it coordinates with both silver and platinum jewelry, yet is cheaper than platinum.
• Platinum:
  This very stylish metal is also the hardest metal, making it for many a symbol of enduring love. Also, because its not mixed with the lesser metals that gold is, platinum is safe for those with allergies. However, you'll pay more for platinum than for gold.

Precious Gems
When considering precious gems, remember that you will likely wear this ring every day for the rest of your life. Therefore, while softer stones can be beautiful, they aren't the best choices for an wedding band or engagement ring. The Mohs scale registers a stone's ability to resist abrasion; 10 (diamonds) is the strongest and 1 (talc) is the weakest. Anything less than a Mohs scale 7 is not recommended for an engagement ring. If you are a person who does a lot of activity with their hands (how long does a manicure last on you?) then I would advise limiting your selection to rubies, sapphires and diamonds. 

To help you out, here's a list of common stones, and their hardness level:
Diamonds 10
Rubies 9
Sapphire 9
Emerald 8
Topaz 8
Aquamarine 7.5 to 8
Amethyst 7
Garnet 6.5 to 7.5
Opal 6

You should also know that a general rule of thumb is the darker the color, the more expensive the stone. 


Diamonds:
Looking to buy a diamond wedding band or engagement ring? Before you do so, read this article to make sure you are well acquainted with the diamond four c's - color, cut, clarity, and caret. 

Resource from: http://weddings.about.com/cs/weddingbands/a/weddingrings.htm